CareerCup

number of bits, simple solution:

int n = 0;
while (x) {
  if (x & 0x1) n++;
  x >>= 1;
}

faster solution (hint from k&r - study difference between x and x - 1)

int n = 0;
while (x) {
  x = x & ~(x ^ (x-1));
  n++;
}

#define getsize(x) ((char *)(&(x) + 1) - (char *)&(x))
int i; getsize(i);



char *strcpy(char *dest, const char *src){
char *save = dest;
while(*dest++ = *src++);
return save;}


Structure padding is adding extra bits at the end of the structue,so that the structure completes the word boundary. Structure padding is used to pad the data in such a way that it can be sent to external devices. Sometimes, the data is padded in such a way that it can be used on little endian vs big endian processors .

To find the number of bits set in a number:

while(num !=0)
num &= num - 1;

Best sol, will run only for the no. Of bits set in the no.

int dig,num_bit=0;
while(dig)
{
num_bit++;
dig = dig>>1;
}